Drive transmission for steerable tractor wheels



July 7, 1953 A. P. BALZER 2,644,

DRIVE TRANSMISSION FOR STEERABLE TRACTOR WHEELS f Filed July 12, 1950 J v 3 Sheets-Sheet l July 7, 1953 P. BALZER 2,644,540

DRIVE TRANSMISSION FOR STEERABLE TRACTOR WHEELS Filed July 12, 1 950 3 Sheets-Sheet 2 July7, 1953 A. P. BALZER "Filed July 12; 1950 DRIVE TRANSMISSION FOR STEERABLE TRACTOR WHEELS 3, Sheet s-Sheet 3 jzwaziar Patented July 7, I953 'VDRIVE TRANSMISSION FOR STEE'RABLE TRACTOR WHEELS Abram P. .Balzer,- Mountain Lake, Application July'l2, 1950, ,Serial'No. 173371 Claim. (Cl-180-26.)

My invention relates generally to tractor construction and more specifically to a steerable drive wheel unit applied to a tractor for farm use.

In tractors of the type employing a single steerable drive wheel, the drive wheel is usually journalled in a forklike member mounted in the tractor frame for steering rotation about a vertical axis, and the wheel is rotated by means of bevel gears or the like, one of which is mounted 'on a shaft extending through the journalled portion of the mounting fork coaxially therewith. It has been found that this type of drive exerts a force on the wheel mounting fork tending toimpart steering rotation thereto and interfering with intentional steering thereof. An important object of my invention therefore, is the provision of a tractor'having a single dirigible drive wheel and driving mechanism therefor which will permit free steering movements of the drive wheel.

Another object of my invention is theprovision of driving mechanism which will impart full driving power to the drive wheel without exerting any steering action to the mounting fork thereof when steering movements are being imparted to the fork by'the operator.

Still another object of my invention is the provision of a tractor of the above type which may be quickly and easily coupled to a wheel-equipped farm implement and be partially supported thereby, and when uncoupled therefrom to be self sustaining.

Another object of my invention is the provision of a tractor as set forth which, when coupled to a farm implement, will enable the implement to be turned about a minimum radius,

Another object of my invention is the provision of means whereby the operator of the tractor may be seated facing either the front or the rear of the tractor and control the same with equal facility from either position.

A still further object of my invention is the provision of a tractor as set forth which, when coupled to an implement has the greater portion of its weight carried by the drive wheel.

Another object of my invention is the provision of a tractor of the above type which is relatively inexpensive to produce, which is efficient in operation, and which is rugged in construction and durable in use.

Other highly important objects and advantages of my invention will become apparent from the following detailed specificatiomappended claim, and attached drawings.

Referring to the drawings, wherein like characters indicate like parts throughout the several views:

Fig. 1 is a view in planofmy novel tractor; Fig. 2 is -a side elevation, some parts being broken away; and I Fig. 3 is an enlarged fragmentary view in end elevation, some parts being broken away and some rearwardly at their upper end portions toward a central driving head ;4. The frame further in cludes a pair of depending legs -5 which support a motor mounting base 6, and to the lower end portions of which are pivotally mounted at one of their ends a pair of arms I, as indicatedat 3. A pair of pneumatic tire-equipped supporting wheels 9 are journalled to the opposite bifurcated ends of the arms I, the intermediate portions of which are -pivotally;secured, asindicated at ill, to the outer ends of a pair of piston-equippedplungers H thatare mounted for extendingand re tracting movements in fluidpressurebperated cylinders [2. The cylinders 12 are pivotally secured at one of their ends to the lower portion of the frame members 2 and 3 respectively, asat l3, and are adapted to have fluid under pressure supplied thereto from suitable pump means not shown, through fluid pressure conduits l4. Fluid under pressure introduced into the cylinders [2 will cause the arms I and the wheels ecarried,

thereby to be moveddownwardly with respect-to the frame I whereby to raise the adjacent end of the frame. On the other hand, when fluid is permitted to return to the source from cylinders Iv-2, the piston plungers ll will be retracted and the wheels 9 moved upwardly with respect to the frame I. V

The rear end portion of the frame I is sup ported by a pneumatic tire-equipped dirigible driving wheel 15, the axle shaft l5 of which is journalled in the lower end of a bifurcated mounting member or fork l6.- The fork I6 15 generally vertically disposed and has its upper portion I! mounted in spaced anti-friction bear ing I8 inlthe head 4 for steering movements about a vertical axis. Steering movements are imparted to the fork l6 and. the wheel l5 join-- nalled therein by mechanism including a sprocket wheel I9 keyed or otherwise rigidly secured to the upper end portion H below the head 4, a second sprocket. '20 fast on the lower end portion of 'a steering shaft 2! which is journalledin a verti"-' cally disposed steering post 22, and anendless link chain 23 running overthe sprockets l9 and 20. The post 22 is rigidly secured by bolts or the fast on the lower end portion of the shaft 21,

these sprockets and 3| being connected by an endless link chain 32, whereby rotation of one of the shafts 2| or 21 will impart rotation to the other thereof and to the steering fork l6 through the connectionsincluding the endless link chain 23. With reference to Figs. 1 and 2 it will be seen that the upper ends 2| and 2'? of the shafts 2| and 21 respectively are cross sectionally rectangular whereby to receive selectively thereon a steering Wheel 33. The steering wheel 33 is provided with a cross sectionally rectangular recess as indicated by dotted lines in Fig. 2 to fit the upper ends 2| and 21 whereby the shafts 2| and 21 may be rotated. An operators seat 34 is mounted on a pedestal-like base 35 for rotation about a vertical axis. The seat 34 may be rotated from a position facing the steering post 22 to its position of Fig. 2 wherein it faces the steering post 28, so that, irrespective of the direction in which the tractor is driven, the operator may face forwardly without undue twisting or turning of his body. 7

My improved tractor is driven from a conventional internal combustion engine 36 having a drive shaft 31 projecting from one end thereof. As shown in Fig. 3, the shaft 3! projects outwardly from a gear housing 38 and is adapted to be rotated in either direction by conventional gearing not shown but contained within a housing 38 and controlled by a gear shift lever 39. A friction clutch 4G operated by suitable means including a shifter fork 41 is utilized to couple the shaft 31 to a variable speed pulley 42 carried by the shaft 31 and an outboard bearing 43. endless V-belt 44 runs over the pulley 42 and over a similar pulley 45 mounted on a jackshaft 46 that is journalled at its opposite ends in bearings 47 mounted on cross bars 48 of the frame l The opposite belt-engaging sides of the pulley 45 are urged toward one another by a coil compression spring 49 whereas the opposite side portions of the pulley 42 are moved toward and away from each other by a; conventional shifter fork 50 engageable with a groove 5| in a hub portion on one of the side elements of the pulley 42. Lateral shifting of the shifter fork 50 causes the belt 44 to drive the jackshaft 41 at varying speedsaccording to the desires of the operator. A pulley 52 is pinned or otherwise rigidly secured to the jackshaft 46 and has running thereover a pair of V-belts 53 which extend upwardly and rear-j wardly and run over a second pulley 54 mounted fast on a power transmission input shaft 55, as

shown in Figs. 1 and 3. The input shaft 55 is journalled in a bearing bracket 56 extending laterally outwardly from the head 4. At its inner end, the input shaft 55 is journalled in a recess 57 opening axially outwardly from the enlarged end 58 of an inner drive shaft 59. The shaft 59 is J'ournalled for rotation in asleeve-like hub 60 projecting laterally outwardly from a housing Bl, the opposite end portion of which is journalled on the input shaft 55 adjacent bearing bracket 56. 1

All.

the outer end of the.

The housing 6| is integrally formed with a. bevel gear 62 coaxial with the input shaft 55 and which is in opposed relationship to a similar bevel gear 63 integrally formed with the enlarged end 58 of the inner drive shaft 59. The input shaft 55 intermediate the gears 62 and 63 is formed to provide an enlarged head 64. A shaft 65 extends through the head 64 and diametrically through theinput shaft 55 and has journalled on the opposite end portions thereof a pair of bevel gears '66 and 61 which have intermeshing engagement with the opposed gears 52 and 63. This arrangement provides a differential drive for the inner drive shaft 59 and the sleeve-like outer drive shaft 6!]. It will be noted by reference to Fig. 3 that the sleeve 69 is mounted for rotation in one end of a casing or the like 68 formed as a portion of the head 4. An antifriction bearing 69 is interposed between the end of the casing 68 and sleeve 30. I

A pair of concentric shafts 10 and H extend vertically through the upper end portion I1 of the drive wheel mounting fork l6 and coaxially therewith. As shown, the shaft 'H is in the nature of a tubular sleeve through which the shaft 10 extends and is journalled in the upper portion H of the mounting member IS. The shaft 19 extends loosely through the tubular shaft H and is journalled at its opposite ends in the casing 68 and in the mounting member [6 as indicated at 12 and 13 respectively. A bevel gear 14 is keyed or otherwise rigidly secured to the upper end of the tubular shaft 1! and has meshing engagement with a bevel pinion mounted fast on the end portion of the sleeve 30. A bevel gear 75 is pinned or otherwise rigidly secured to the upper end portion of the shaft 19 in opposed relationship to the gear I4 and has meshing engagement with a bevel pinion 11 mounted fast on the inner drive shaft 59; It will be noted that the relative diameters of the bevel gears 14 and I6 and the bevel pinions I5 and I1 normally cause the concentric shafts Hi and H to be rotated at identical speeds, and that the opposed relationship between the bevel gears 14 and 16 causes the concentric shafts l0 and H to be rotated in opposite directions. The steering fork I5 is formed to provide a chamber 78 into which the outer concentric shaft 'H projects and through which the inner shaft 10 extends. The lower end of the shaft "H is formed to provide a bevel gear 80 which is in opposed relationship to a like bevel gear 8| rigidly secured to the lower end portion of the shaft 70. shaft 8| is journalled in one side Wall of the chamber 18 in parallel relationship to the axis of rotation of the drive wheel I5, and has rigidly secured to its inner end a bevel gear 22, diametrically opposed portions of which have simultaneous meshing engagement with the gears 19 and 80. to the outer end of the countershaft BI and has running thereover an endless link chain 84. Said link chain 84 also runs over a relativelylarge sprocket wheel mounted fast on the outer end of the steering wheel shaft l5 whereby to im part rotation to the wheel l5.

From the above, it should be obvious that torque thrust exerted on the bevel gear 82 by the opposed bevel gears 19 and 80 occurs in opposite directions so that there is no tendency for the fork it to rotate about the axis of the head 11 thereof when a relatively heavy turningload is placed on the'wheel l5. When the tractor is A counter- A sprocket wheel 83 is rigidly secured being driven around a corner or the like,;the

steering fork l6 and wheel l5 carried thereby are rotated about the axis of the head I! in the same direction as one of the bevel gears I4 and '16. When this occurs, one of the pinions I5 and 11 tends to rotate at a greater speed than the other thereof. are equalized by the differential gears in the housing 61. By this means, the speeds of rotation of the concentric shafts and H remain constant with respect to one another.

As above indicated, my improved tractor is particularly adapted to be used in connection with wheel-equipped farm implements such as cultivators, swathers, and the like. Diagrammatically shown in Figs. 1 and 2 are a plurality, preferably 3, of automatic couple-rs 86 one of which is rigidly secured to the platform and the others of which are mounted on a cross bar 8'! secured to the lower end portions of the frame members 2 and 3. The couplers 86 may be of any of the types in common usage, but are preferably of the type disclosed in my prior Patent No. 2,478,736.

tongues 88, indicated by broken lines in Fig. 2, said tongues being suitably secured to the implement, the implement being indicated in its entirety by 89.

When it is desired to utilize my novel tractor to drive a farm implement, the supporting wheels 9 are raised or lowered as desired to bring the automatic couplers 86 into alignment with the tongues 33. The tractor is then moved in the direction of the tongues 88 until they become locked in the coupler B6, whereupon the wheels 9 are raised out of supporting engagement with the ground. Raising of the wheels 9 from contact with the ground causes the greater portion of the weight of the tractor to be supported by the dirigible drive wheel l5, whereby sufiicient traction is provided to permit the tractor to effectively propel the implement 89. In the event that the implement 89 is of the type which normally operates behind a tractor, the operator I merely places the steering wheel 33 on the end 2| of the steering shaft 21 and revolves the operator's seat 180 degrees from its position shown in Figs. 1 and 2 so that he is facing forwardly in the desired direction of travel.

From the above, it should be obvious that I have provided a tractor which is fully capable of accomplishing the objectives set forth; and :while I have disclosed a commercial embodiment of my improved tractor, it will be understood that the same is capable of modification without departure from the spirit and scope of the invention as defined in the claim.

What I claim is:

A vehicle having a single combined traction As indicated in Fig. 2, the cou-- ple-rs 86 are adapted to receive cooperating The speeds of the pinions l5 and 11 journalled in the frame and driven by said engine,

a bevel gear mounted on said input shaft and rotatable about an axis at right angles to the axis of rotation of said input shaft, a pair of opposed bevel gears coaxial with said input shaft and having meshing engagement with saidfirstmentioned bevel gear, said pair of bevel gears terminating in drive shafts each having a drive ear on its outer end, a pair of concentric shafts rotatably mounted in the upper end of saidfork and coaxial therewith, a pair of opposed gears one each on the upper end of each of said'concentric shafts and each operatively associated with one of said drive gears, whereby the-concentric shafts are rotated in opposite directions at like'speeds, a pair of axially spaced opposed, equalizer gears on the lower ends of the-con-. centric shafts, a countershaft journalled for rotation in said fork about an axis in spaced parallel relationship to the axis of said traction wheel, a gear fast on the countershaft and having diametrically opposed portions in meshing engagement simultaneously with said opposed equalizer 1 gears, and driving connections between the countershaft and the traction wheel at one side only of said fork, said driving connections including a pair of sprocket wheels one each secured to the countershaft and traction wheel and a link chain. running over said sprocket wheels in driving engagement therewith.

, i, ABRAM P. BALZER.

References Cited in the file of thispatent UNITED STATES PATENTS Number Name Date 644,610 Knight Mar. 6, 1900 1,191,333 Montgomery et al. July 18, 1916 1,282,033 Blewett Oct. 22, 1918 1,353,192 Tinker Sept. 21, 1920 2,333,611 Wolf Nov. 2, 1943 2,421,867 Bizjak June 10, 1947 FOREIGN PATENTS Number Country Date 1 180,579 Germany .1 Jan.'21, 1907 

